Topic: Articles

Minding the Corners

It’s all about the clay: how it feels in your hands, on your fingertips; how it can be shaped and decorated into useful, beautiful objects. Timing is crucial when working with clay. The many stages of drying clay give us opportunities to manipulate and form the visions we hold. In this article, I hope to share with you what I have come to learn about the sgraffito technique and how important timing is to the process.

Sgraffito, an Italian word meaning to scratch, is a form of decoration made by carving through a slip or underglaze surface on leather-hard clay to reveal the contrasting color of the clay body. This technique has been used by many cultures throughout history by not only the Italians, but also the Germans, Austrians, and Spanish.

New Opportunities, Changes Over Time

After graduating with my BFA, I discovered the Kirkland Arts Center in Kirkland, Washington, and instructor Larry Halvorsen while looking for a studio space. I immediately connected with Halvorsen’s work. A sgraffito master, his work reflects nature in both the forms and the sgraffito patterns on his surfaces, giving the viewer a sense of rhythm and movement. After some time taking his class, he offered me a job working for him at his studio.

I spent hours observing the way he cut through the clay with confidence, leaving marks and patterns that fit his forms. There was an assuredness as he went about his process and I could see his passion for what he was making come through.

That was 20 years ago; life happened, and now I’m back into clay and the sgraffito process. As my loop tool carved through the clay, I was immediately hooked again by the feeling, and by seeing the curls of clay lifting up and an image come through. Sgraffito is addictive to say the least.

Teapot, stoneware, blue slip, fired to cone 6, 2018.

Mugs and service ware, stoneware, fired to cone 6.

Creating the Right Form for Sgraffito

The best clay body for use with sgraffito is ideally a smooth one, because it is easier to carve through. If the clay has a lot of grog, your tools will catch on those pieces of fired clay and sand and will cause your tool to jump, creating jagged and inconsistent lines.

While I find that a dark clay with a white slip is beautiful, I use a mid-range white stoneware. It’s a versatile clay body that I can throw, handbuild, and carve. I like the off-white color after it’s glazed and fired because it contrasts well with the dark slip so my marks can be seen.

Forms with smooth, even surfaces are the easiest to sgraffito; however, I have sgraffitoed hand-pinched forms and have discovered that uneven surfaces add interest to the sgraffito technique.

1 Apply two even coats of slip to the leather-hard clay form. Allow the slip to dry between coats.

2 Using a dull pencil, sketch your design or pattern onto the chalky slip surface.

Making Slip

I make the slip I use; however, you can use commercial underglazes with great success. Making slip requires adding dried pieces of your clay body to water. Using a slip made from your own clay body assures a better binding relationship between the clay body and the slip, helping to prevent peeling and flaking.

To make the slip, put your dried trimmings into a bucket and cover the trimmings with water, to about an inch above the top height of the clay. Let this sit overnight to slake down the clay. In the morning, stir the clay and run it through a 28-mesh sieve. The sieved clay should have the consistency of pudding. Add small amounts of water if it’s difficult to get the slip to pass through the sieve.

Now you can add Mason stains to color the slip. I add 5–10% black Mason stain to my slip. It’s possible to layer colored slips to get various effects. Try experimenting on test tiles you can fire and reference later. I have stuck with the black color because it reminds me of river rocks and it’s a simple, straightforward look.

3 With a small loop tool, outline the negative spaces of the drawn design or pattern.

4 Continue to outline the drawn design or pattern. Once the clay shavings are dry, they can be cleared from the surface.

Prepping the Surface with Slip

Apply two coats of slip to your leather-hard clay form (1). This will give an even, opaque coverage. Wait for the slip to feel a little chalky as you run the pads of your fingers across the surface. Once it does, the surface is ready for you to draw your design.

Using a dull pencil, lightly sketch your design, light enough to show up but not cut through the slip (2). Patterns that I have found to work best are ones with bold clear shapes. But if you can imagine it, go for it

I find this chalky stage to be the most ideal surface to start carving on. The slip and the clay will not gum up your loop tools and the slip residue left behind is minimized as you carve. The clay should curl up, similar to how the clay feels and behaves when trimming a pot on the wheel.

5 When carving, rotate your plate to suit the best angle for carving and to be sure not to smudge your surface.

6 Once you’re finished outlining the carving, carefully remove the shavings without creating hazardous dust.

Sgraffito Process

Start with a small loop tool and follow your pencil lines to outline the shapes (3, 4). Hold your plate at any angle that’s comfortable for you, but be sure that your hand doesn’t rest on the plate as you work or you may smudge your slip and carving work (5, 6). I often prefer a 45° angle when carving and adjust the hold and angle depending on the form or where I’m sitting. Start with a small loop tool and follow your pencil outlines. With my flower patterns, I focus on outlining the negative spaces. This allows some overlapping of the images so the flowers don’t appear like they were simply cut out with a cookie cutter.

After you have outlined the negative spaces, then go back with various larger loop tools and carve out the negative areas (7, 8). This step creates bold images and various flower and leaf shapes. I then go back with a small loop tool and carve the detail work within the flower shapes and leaves (9). If I make a mistake in the carving process, I go back and fill in the area with slip, then start over once again. This is a very forgiving process.

7 With the design now outlined, begin to lightly remove the slip from the negative spaces.

8 By taking away the background, you will start to see your design pop out and come away from the surface.

9 Go back and clean up any ragged corners and add image details with a small loop tool.

Nicole Pepper displays a stack of her blue-and-white sgraffito plates and platters.

Mind Your Corners

It’s important to mind your corners. If you don’t go back into those tiny corners and make sure all the burrs are cleaned up and all the edges are fully refined, they could jump up onto the glazed surface in the firing process. These aren’t only visible eyesores, but worse, they can leave a sharp point that could cut your hand or could chip off, ruining your plate.

Sgraffito provides a means to decorate the surface of clay with clarity and leave a warm, handcrafted feel due to the carved surface. I hope this inspires you to play with slips and get carving!

Thank you to my photographer, Chandra Sandoval, for all the creative and wonderful photos.

Nicole Pepper graduated from Western Washington University with a BFA in ceramics. Her current work can be viewed on Instagram at modhome.ceramics and on her website at

  • Dani M.

    Thank you for sharing. I also enjoy sgraffito but your article encouraged me to start experimenting making my own slip

  • Marie T.

    Thank you Nicole for generously sharing your technique, passion and love for clay, process and design! Beautiful work and a beautiful person!

  • Silvia A.

    Love, love, love your work, thank you so much for generously sharing. Question please if you add black stain to slip, why it looks navy?

  • Matthew W.

    Thank you for sharing your work, techniques, ideas, advice, and clearly your passion. This was mot one of your typical how-too articles, not that those are not well written and informative, but you began your piece by allowing the readers, to get to know you a little by expressing your feelings about what you do and what you put into your work which is a part of you going into every piece you create. You are accomplishing your goal. I not only received instruction but I can tell you it was a joy to read about you and the way you put joy into every piece. Thank you. Best wishes to you.

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